//
// https://github.com/ServiceStack/ServiceStack.Redis
// ServiceStack.Redis: ECMA CLI Binding to the Redis key-value storage system
//
// Authors:
//   Demis Bellot (demis.bellot@gmail.com)
//
// Copyright 2013 ServiceStack, Inc. All Rights Reserved.
//
// Licensed under the same terms of ServiceStack.
//

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ServiceStack.Model;
using ServiceStack.Redis.Pipeline;
using ServiceStack.Text;

namespace ServiceStack.Redis.Generic;

/// <summary>
/// Allows you to get Redis value operations to operate against POCO types.
/// </summary>
/// <typeparam name="T"></typeparam>
public partial class RedisTypedClient<T>
    : IRedisTypedClient<T>
{
    static RedisTypedClient()
    {
        Redis.RedisClient.__uniqueTypes.Add(typeof(T));
    }

    readonly ITypeSerializer<T> serializer = new JsonSerializer<T>();
    private readonly RedisClient client;

    public IRedisClient RedisClient => client;

    public IRedisNativeClient NativeClient => client;

    /// <summary>
    /// Use this to share the same redis connection with another
    /// </summary>
    /// <param name="client">The client.</param>
    public RedisTypedClient(RedisClient client)
    {
        this.client = client;
        this.Lists = new RedisClientLists(this);
        this.Sets = new RedisClientSets(this);
        this.SortedSets = new RedisClientSortedSets(this);

        this.SequenceKey = client.GetTypeSequenceKey<T>();
        this.TypeIdsSetKey = client.GetTypeIdsSetKey<T>();
        this.TypeLockKey = string.Concat(client.NamespacePrefix, "lock:", typeof(T).Name);
        this.RecentSortedSetKey = string.Concat(client.NamespacePrefix, "recent:", typeof(T).Name);
    }

    private readonly string RecentSortedSetKey;
    public string TypeIdsSetKey { get; set; }
    public string TypeLockKey { get; set; }

    public IRedisTypedTransaction<T> CreateTransaction()
    {
        return new RedisTypedTransaction<T>(this, false);
    }

    public IRedisTypedPipeline<T> CreatePipeline()
    {
        return new RedisTypedPipeline<T>(this);
    }
    public IDisposable AcquireLock()
    {
        return client.AcquireLock(this.TypeLockKey);
    }

    public IDisposable AcquireLock(TimeSpan timeOut)
    {
        return client.AcquireLock(this.TypeLockKey, timeOut);
    }

    public IRedisTransactionBase Transaction
    {
        get => client.Transaction;
        set => client.Transaction = value;
    }

    public IRedisPipelineShared Pipeline
    {
        get => client.Pipeline;
        set => client.Pipeline = value;
    }

    public void Watch(params string[] keys)
    {
        client.Watch(keys);
    }

    public void UnWatch()
    {
        client.UnWatch();
    }

    public void Multi()
    {
        this.client.Multi();
    }

    public void Discard()
    {
        this.client.Discard();
    }

    public void Exec()
    {
        client.Exec();
    }

    internal void AddTypeIdsRegisteredDuringPipeline()
    {
        client.AddTypeIdsRegisteredDuringPipeline();
    }

    internal void ClearTypeIdsRegisteredDuringPipeline()
    {
        client.ClearTypeIdsRegisteredDuringPipeline();
    }

    public List<string> GetAllKeys()
    {
        return client.GetAllKeys();
    }

    public string UrnKey(T entity)
    {
        return client.UrnKey(entity);
    }

    public IRedisSet TypeIdsSet => TypeIdsSetRaw;

    private RedisClientSet TypeIdsSetRaw => new RedisClientSet(client, client.GetTypeIdsSetKey<T>());

    public T this[string key]
    {
        get => GetValue(key);
        set => SetValue(key, value);
    }

    public byte[] SerializeValue(T value)
    {
        var strValue = serializer.SerializeToString(value);
        return Encoding.UTF8.GetBytes(strValue);
    }

    public T DeserializeValue(byte[] value)
    {
        var strValue = value != null ? Encoding.UTF8.GetString(value) : null;
        return serializer.DeserializeFromString(strValue);
    }

    public void SetValue(string key, T entity)
    {
        if (key == null)
            throw new ArgumentNullException(nameof(key));

        client.Set(key, SerializeValue(entity));
        client.RegisterTypeId(entity);
    }

    public void SetValue(string key, T entity, TimeSpan expireIn)
    {
        if (key == null)
            throw new ArgumentNullException(nameof(key));

        client.Set(key, SerializeValue(entity), expireIn);
        client.RegisterTypeId(entity);
    }

    public bool SetValueIfNotExists(string key, T entity)
    {
        var success = client.SetNX(key, SerializeValue(entity)) == RedisNativeClient.Success;
        if (success) client.RegisterTypeId(entity);
        return success;
    }

    public bool SetValueIfExists(string key, T entity)
    {
        var success = client.Set(key, SerializeValue(entity), exists:true);
        if (success) client.RegisterTypeId(entity);
        return success;
    }

    public T GetValue(string key)
    {
        return DeserializeValue(client.Get(key));
    }

    public T GetAndSetValue(string key, T value)
    {
        return DeserializeValue(client.GetSet(key, SerializeValue(value)));
    }

    public bool ContainsKey(string key)
    {
        return client.Exists(key) == RedisNativeClient.Success;
    }

    public bool RemoveEntry(string key)
    {
        return client.Del(key) == RedisNativeClient.Success;
    }

    public bool RemoveEntry(params string[] keys)
    {
        return client.Del(keys) == RedisNativeClient.Success;
    }

    public bool RemoveEntry(params IHasStringId[] entities)
    {
        var ids = entities.Map(x => x.Id);
        var success = client.Del(ids.ToArray()) == RedisNativeClient.Success;
        if (success) client.RemoveTypeIdsByValues(ids.ToArray());
        return success;
    }

    public long IncrementValue(string key)
    {
        return client.Incr(key);
    }

    public long IncrementValueBy(string key, int count)
    {
        return client.IncrBy(key, count);
    }

    public long DecrementValue(string key)
    {
        return client.Decr(key);
    }

    public long DecrementValueBy(string key, int count)
    {
        return client.DecrBy(key, count);
    }

    public string SequenceKey { get; set; }

    public void SetSequence(int value)
    {
        client.GetSet(SequenceKey, Encoding.UTF8.GetBytes(value.ToString()));
    }

    public long GetNextSequence()
    {
        return IncrementValue(SequenceKey);
    }

    public long GetNextSequence(int incrBy)
    {
        return IncrementValueBy(SequenceKey, incrBy);
    }

    public RedisKeyType GetEntryType(string key)
    {
        return client.GetEntryType(key);
    }

    public string GetRandomKey()
    {
        return client.RandomKey();
    }

    public bool ExpireEntryIn(string key, TimeSpan expireIn)
    {
        return client.ExpireEntryIn(key, expireIn);
    }

    public bool ExpireEntryAt(string key, DateTime expireAt)
    {
        return client.ExpireEntryAt(key, expireAt);
    }

    public bool ExpireIn(object id, TimeSpan expireIn)
    {
        var key = client.UrnKey<T>(id);
        return client.ExpireEntryIn(key, expireIn);
    }

    public bool ExpireAt(object id, DateTime expireAt)
    {
        var key = client.UrnKey<T>(id);
        return client.ExpireEntryAt(key, expireAt);
    }

    public TimeSpan GetTimeToLive(string key)
    {
        return TimeSpan.FromSeconds(client.Ttl(key));
    }

    public void Save()
    {
        client.Save();
    }

    public void SaveAsync()
    {
        client.SaveAsync();
    }

    public void FlushDb()
    {
        client.FlushDb();
    }

    public void FlushAll()
    {
        client.FlushAll();
    }

    public T[] SearchKeys(string pattern)
    {
        var strKeys = client.SearchKeys(pattern);
        return SearchKeysParse(strKeys);
    }
    private T[] SearchKeysParse(List<string> strKeys)
    {
        var keysCount = strKeys.Count;

        var keys = new T[keysCount];
        for (var i = 0; i < keysCount; i++)
        {
            keys[i] = serializer.DeserializeFromString(strKeys[i]);
        }
        return keys;
    }

    public List<T> GetValues(List<string> keys)
    {
        if (keys.IsNullOrEmpty()) return new List<T>();

        var resultBytesArray = client.MGet(keys.ToArray());
        return ProcessGetValues(resultBytesArray);
    }
    private List<T> ProcessGetValues(byte[][] resultBytesArray)
    {
        var results = new List<T>();
        foreach (var resultBytes in resultBytesArray)
        {
            if (resultBytes == null) continue;

            var result = DeserializeValue(resultBytes);
            results.Add(result);
        }

        return results;
    }

    public void StoreAsHash(T entity)
    {
        client.StoreAsHash(entity);
    }

    public T GetFromHash(object id)
    {
        return client.GetFromHash<T>(id);
    }


    #region Implementation of IBasicPersistenceProvider<T>

    public T GetById(object id)
    {
        var key = client.UrnKey<T>(id);
        return this.GetValue(key);
    }

    public IList<T> GetByIds(IEnumerable ids)
    {
        if (ids != null)
        {
            var urnKeys = ids.Map(x => client.UrnKey<T>(x));
            if (urnKeys.Count != 0)
                return GetValues(urnKeys);
        }

        return new List<T>();
    }

    public IList<T> GetAll()
    {
        var allKeys = client.GetAllItemsFromSet(this.TypeIdsSetKey);
        return this.GetByIds(allKeys.ToArray());
    }

    public T Store(T entity)
    {
        var urnKey = client.UrnKey(entity);
        this.SetValue(urnKey, entity);
        return entity;
    }

    public T Store(T entity, TimeSpan expireIn)
    {
        var urnKey = client.UrnKey(entity);
        this.SetValue(urnKey, entity, expireIn);
        return entity;
    }

    public void StoreAll(IEnumerable<T> entities)
    {
        if (PrepareStoreAll(entities, out var keys, out var values, out var entitiesList))
        {
            client.MSet(keys, values);
            client.RegisterTypeIds(entitiesList);
        }
    }

    private bool PrepareStoreAll(IEnumerable<T> entities, out byte[][] keys, out byte[][] values, out List<T> entitiesList)
    {
        if (entities == null)
        {
            keys = values = default;
            entitiesList = default;
            return false;
        }

        entitiesList = entities.ToList();
        var len = entitiesList.Count;

        keys = new byte[len][];
        values = new byte[len][];

        for (var i = 0; i < len; i++)
        {
            keys[i] = client.UrnKey(entitiesList[i]).ToUtf8Bytes();
            values[i] = Redis.RedisClient.SerializeToUtf8Bytes(entitiesList[i]);
        }
        return true;
    }

    public void Delete(T entity)
    {
        var urnKey = client.UrnKey(entity);
        this.RemoveEntry(urnKey);
        client.RemoveTypeIdsByValue(entity);
    }

    public void DeleteById(object id)
    {
        var urnKey = client.UrnKey<T>(id);

        this.RemoveEntry(urnKey);
        client.RemoveTypeIdsById<T>(id.ToString());
    }

    public void DeleteByIds(IEnumerable ids)
    {
        if (ids == null) return;

        var idStrings = ids.Map(x => x.ToString()).ToArray();
        var urnKeys = idStrings.Select(t => client.UrnKey<T>(t)).ToArray();
        if (urnKeys.Length > 0)
        {
            this.RemoveEntry(urnKeys);
            client.RemoveTypeIdsByIds<T>(idStrings);
        }
    }

    private void DeleteAll(ulong cursor, int pageSize)
    {
        do
        {
            var scanResult = client.SScan(this.TypeIdsSetKey, cursor, pageSize);
            cursor = scanResult.Cursor;
            var ids = scanResult.Results.Select(x => Encoding.UTF8.GetString(x)).ToList();
            var urnKeys = ids.Map(t => client.UrnKey<T>(t));
            if (urnKeys.Count > 0)
            {
                this.RemoveEntry(urnKeys.ToArray());
            }
        } while (cursor != 0);

        this.RemoveEntry(this.TypeIdsSetKey);
    }
        
    public void DeleteAll()
    {
        DeleteAll(0,RedisConfig.CommandKeysBatchSize);
    }

    #endregion

    internal void ExpectQueued()
    {
        client.ExpectQueued();
    }
    internal void ExpectOk()
    {
        client.ExpectOk();
    }
    internal int ReadMultiDataResultCount()
    {
        return client.ReadMultiDataResultCount();
    }
    public void FlushSendBuffer()
    {
        client.FlushAndResetSendBuffer();
    }
    public void ResetSendBuffer()
    {
        client.ResetSendBuffer();
    }
    internal void EndPipeline()
    {
        client.EndPipeline();
    }
}